As the telecommunications industry develops, signaling is more frequently exchanged between a user equipment (UE), a base station, and a network element of a core network (CN). Therefore, the UE needs to listen to information about a paging channel in real time, so as to ensure that when the CN delivers a paging message to the UE, the UE can listen to the paging message synchronously; however, the real-time listening by the UE increases power consumed by the UE.
To reduce the power consumed by a UE, in the prior art, a discontinuous reception (DRX) technology is introduced, that is, the UE stops listening on a channel and stays in a sleep state for a period of time, and wakes up every a period of time. A system may indicate a time interval between each waking of the UE. In this way, when receiving a downlink service, a network element of a core network delivers a paging message only at a time when the UE wakes up, so as to achieve a purpose of saving power for the UE. However, this technology needs a mechanism to ensure synchronization of a listening time of the UE and a time when a network delivers paging; otherwise, a paging failure may occur. In an existing DRX technology, a UE sends a non-access stratum (NAS) request message that carries a DRX value to a network element of a core network; the network element of the core network sends a paging message that carries the DRX value to the base station after receiving the request message; the base station also broadcasts a default DRX value, compares the foregoing two DRX values, selects a smaller one to calculate a paging time, and then sends the paging message at the paging time. The UE also compares the default DRX value broadcast by the base station with the DRX value provided by the UE to the network element of the CN, and selects a smaller one to calculate a time when the UE receives the paging message, thereby ensuring synchronization of paging time of the UE and the network.
However, in the prior art, generally the default DRX value broadcast by the base station is relatively small, which causes that the UE frequently wakes up to listen on a paging channel, and therefore power consumed by the UE cannot be reduced desirably. In addition, when the UE reports longer DRX cycle, if the base station still uses the default DRX, it may causes that DRX of the UE and DRX of the network are asynchronous, thereby paging message loss.